Masaaki Matsunaga

BACKGROUND: Work-related stress is associated with cardiovascular disease (CVD), yet the contributions of specific work-related stressors, support and satisfaction to CVD incidence are not fully understood. Clarifying whether lifestyle behaviors and physiological factors mediate associations between stressors and CVD is essential for targeted prevention. METHODS: In this prospective cohort study, a cohort of 4,820 Japanese workers (3,876 men and 944 women) aged 35-65 years was followed up for CVD incidence from 2007 to 2022. Work-related stressors (e.g., quantitative job overload), support (e.g., supervisor support) and satisfaction (e.g., family life satisfaction) were assessed using the 57-item Brief Job Stress Questionnaire. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD risk. Mediation analysis evaluated the role of lifestyle behaviors (e.g., smoking, alcohol consumption) and physiological factors (e.g., systolic blood pressure, obesity) in the association between stressors and CVD incidence. RESULTS: Quantitative job overload, low supervisor support, and low family life satisfaction were independently associated with increased CVD incidence (HRs ranging from 1.69 to 2.33). A part (24.9%) of the association of quantitative job overload with CVD was significantly mediated by obesity (p=0.007). CONCLUSION: Quantitative job overload, lack of supervisor support, and low family life satisfaction were significant predictors of CVD among Japanese civil servants. These findings suggest that both reducing excessive workload and strengthening support systems inside and outside the workplace may be important for cardiovascular disease prevention among Japanese civil servants.

PURPOSE: This study aimed to (1) identify distinct multidimensional fatigue profiles among employed cancer survivors, (2) examine associations between workplace factors and these profiles, and (3) assess how these profiles are associated with occupational outcomes. METHODS: Seventy-two employed cancer survivors aged 27 to 64 years (median 9.4 years since diagnosis) from a local government in Japan completed questionnaires in 2023 assessing cancer-related fatigue (Cancer Fatigue Scale), workplace factors (job demands, job control, workplace support), and occupational outcomes (work engagement, presenteeism, cognitive function at work, and quality of life). Fatigue profiles were identified using hierarchical cluster analysis. Associations between workplace factors and profiles were examined using multinomial logistic regression. Occupational outcome differences among profiles were examined using linear regression. RESULTS: Three profiles were identified: Low Global Fatigue (n = 12), Dominant Mental Fatigue (n = 36), and High Global Fatigue (n = 24). Workplace support-particularly supervisor understanding, colleague understanding, and schedule flexibility-was associated with approximately 75% lower odds of belonging to the High Global Fatigue group. Job demands and job control showed no associations. The High Global Fatigue group reported lower work engagement, higher presenteeism, reduced cognitive function at work, and poorer quality of life compared to the other groups. CONCLUSIONS: Three multidimensional fatigue profiles were identified among employed cancer survivors. Workplace support factors were more strongly associated with fatigue profiles than job characteristics. These profiles were associated with occupational outcomes. IMPLICATION FOR CANCER SURVIVORS: These distinct fatigue profiles can guide personalized workplace interventions to optimize support for employed cancer survivors.

OBJECTIVES: Various factors influence urinary hippuric acid concentrations; however, the role of climatic factors on such concentrations has not been thoroughly investigated. METHODS: This study examined the correlation between urinary hippuric acid concentrations and climatic factors. Data were obtained from health examinations of 2236 employees at a large manufacturing company who used organic solvents over a 3-year period. Each participant underwent a health examination for organic solvent use during both the summer (June to August) and winter (December to February). Urinary hippuric acid concentrations were log-transformed, and a linear mixed-effects model was applied to assess their association with average temperature, relative humidity, and atmospheric pressure recorded in Nagoya City, Japan. RESULTS: In a multivariate linear mixed-effects model including all meteorological variables, average temperature showed a significant positive association with log-transformed urinary hippuric acid concentrations (estimate = 0.013; 95% CI: 0.007-0.020; P < .001). This corresponds to an estimated 1.3% increase in urinary hippuric acid concentrations per 1°C rise in temperature. In contrast, neither average atmospheric pressure nor relative humidity showed a statistically significant association (P = .981 and P = .817, respectively). Among the confounding variables, smoking was significantly positively associated with concentration (P = .001), whereas alcohol consumption showed a significant negative association (P = .031). CONCLUSIONS: Urinary hippuric acid concentrations exhibited seasonal variation among workers at a large manufacturing company, with elevated levels observed during the summer. These findings underscore the importance of considering climatic factors when interpreting urinary metabolic biomarkers.

BACKGROUND: Insulin resistance in adipocytes, manifested as high basal circulating free fatty acid (FFA) is thought to contribute to the development of type 2 diabetes mellitus (T2DM). However, the association between adipocyte insulin resistance (Adipo-IR) index and T2DM has rarely been explored in prospective studies. We examined this association in a middle-aged Japanese workers' cohort. Since the association may differ according to the degree of overall adiposity, the analysis was stratified by the presence of overweight/obesity defined with body mass index (BMI). METHODS: A total of 3,257 subjects (men 2501, women 756) aged 35-66 years were followed-up for up to 17 years. T2DM incidence was defined as fasting blood glucose level ≥126 mg/dL, glycated hemoglobin level ≥6.5%, or self-reported initiation of glucose-lowering medications. Adipo-IR was calculated as the product of FFA (mmol/L) and insulin (pmol/L) obtained from baseline fasting blood samples and divided into sex- and BMI category (<25 or ≥25 kg/m2)-specific tertiles. Cox-proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for age, BMI, smoking status, physical activity, drinking habit, and family history of diabetes. RESULTS: During a median of 14.6 years of follow-up, 365 developed T2DM. Compared with the lowest tertile, T2DM risk was significantly increased among the highest tertile category in overweight/obese men (HR 2.94; 95% CI, 1.76-4.90) and women (HR 4.24; 95% CI, 1.08-16.61). CONCLUSION: Adipo-IR was positively associated with T2DM risk in overweight/obese men and women.

BACKGROUND: Although bronchoscopic biopsy serves as a cornerstone for diagnosing lung cancer in elderly patients, whether this procedure leads to clinically relevant outcomes is still unclear. This study aimed to clarify the clinical significance of diagnostic bronchoscopy in lung cancer patients aged ≥80 years. METHODS: We retrospectively analyzed 803 patients diagnosed with lung cancer who underwent bronchoscopy at our hospital from April 2015 to March 2019. Those aged ≥80 years and <80 years were classified as the elderly group (n = 154) and young group (n = 649), respectively. RESULTS: The diagnostic yield of bronchoscopy in the elderly and young groups was 92.9 % and 83.5 %, respectively; complication rates were 9.6 % and 7.2 %. Approximately 89 % of the patients in the elderly group received specific lung cancer treatment. The 5-year survival rates for elderly and young patients who underwent surgery were 74.5 % and 78.2 %, respectively. In the elderly group, 11 % of the patients chose best supportive care (BSC) only, compared with 2 % in the young group. Notably, patients with non-diagnostic bronchoscopic results selected BSC more frequently in the elderly versus young groups (30.4 % versus 0 %, respectively). CONCLUSIONS: Bronchoscopy in elderly patients with lung cancer demonstrated a high diagnostic yield and an acceptable safety profile, enabling specific treatments in the majority of cases. These findings support the clinical usefulness of bronchoscopy in guiding treatment decisions for elderly patients. However, non-diagnostic results were associated with a higher likelihood of BCS, highlighting the importance of achieving a definitive diagnosis in this population.

Chronotype, which reflects an individual's preference for activity and sleep timing, has been associated with various chronic conditions, particularly the evening chronotype. Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that collectively increase the risk of developing type 2 diabetes mellitus and cardiovascular diseases. Previous studies on chronotype and MetS have been inconsistent, and none has explored the longitudinal association between MetS and its components. Therefore, this study investigated these associations in middle-aged Japanese civil servants. We analyzed 2231 non-rotating, non-night shift workers (aged 29-69, 71.6% male) from the Aichi Workers' Cohort Study who participated in surveys in 2018 (baseline) and 2022 and were free of MetS at baseline. Participants were classified into morning, evening, or intermediate chronotypes using the shortened Morningness - Eveningness Questionnaire. MetS was defined according to the harmonized criteria for Japanese, based on waist circumference (≥85 cm for men and ≥90 cm for women), triglycerides, HDL cholesterol, blood pressure, and blood sugar levels. Over 4 y, 232 participants (10.4%) developed MetS, with a cumulative incidence rate of 9.9% in morning, 17.6% in evening, and 9.5% in intermediate types. Logistic regression analysis adjusted for sex, age, educational background, occupation, leisure-time physical activity, alcohol intake, sleep duration, smoking status, snoring, night-time awakening, sleep medication use, working hours, breakfast eating habit, and medication use for diabetes, hypertension, and dislipdemia, revealed that the evening type individuals had a significantly higher risk of MetS (OR: 2.30, 95% CI: 1.48-3.57) compared to intermediate types. In conclusion, evening chronotype was independently associated with a higher risk of developing MetS in middle-aged Japanese civil servants.

ABSTRACT Objective To examine the characteristics associated with happiness in Japanese individuals with schizophrenia. Methods A self‐reported online survey was conducted in 2022 among individuals aged 20–75 years, including 223 and 1776 individuals with and without schizophrenia, respectively. We used a modified Poisson regression to assess the factors associated with happiness by calculating the age‐ and sex‐adjusted prevalence ratios (PRs). We examined within‐schizophrenia group differences by age and sex strata, and compared these stratified PRs between groups with and without schizophrenia. Results Among participants with schizophrenia, happiness was significantly associated with self‐rated health status (PR = 1.75), Ikigai (PR = 5.02), depressive symptoms (PR = 0.43), perceived stress (PR = 0.52), cognitive social capital (PR = 2.07), structural social capital (PR = 1.70), social support (PR = 2.40), close friends (PR = 1.88), close relatives (PR = 2.34), and a cohabiting partner (PR = 1.57). Within the schizophrenia group, sex differences were significant for cognitive social capital (men: PR = 3.45; women: PR = 1.43) and cohabiting partners (men: PR = 2.26; women: PR = 1.25), whereas no significant age differences were found. Factors demonstrating a stronger association in participants with schizophrenia than in those without schizophrenia included: Ikigai (with, PR = 5.02; without, PR = 2.91), cognitive social capital (with, PR = 2.07; without, PR = 1.49), and structural social capital (with, PR = 1.70; without, PR = 1.24). Conclusion Happiness in individuals with schizophrenia is associated with physical, mental, and social factors, with social factors exhibiting sex‐related differences.

Better identification of individuals at high risk for type 2 diabetes mellitus (T2DM) requires risk-prediction models incorporating novel predictors. Accordingly, this study aimed to evaluate the merits of including long-term systolic blood pressure variability (SBPV) in predicting T2DM incidence in a Japanese cohort of 3017 participants (2446 men, 571 women; age, 36-65 years) in 2007, who were followed up until March 2019. Consecutive SBP values, recorded between 2003 and 2007, were regressed annually for each participant. The slope and root-mean-square error of the regression line were calculated for each individual to represent SBPV. The significance of SBPV was examined by adding it to a multivariate Cox model incorporating age, sex, smoking status, regular exercise, family history of diabetes, body mass index, blood levels of triglycerides, high-density lipoprotein cholesterol, and fasting blood glucose. The c-index, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to compare the performance of the prediction models without (Model 1) and with (Model 2) SBPV. During the 9.8-year follow-up period, 135 participants developed T2DM. Although a statistically significant difference in c-index between Model 1 (0.785) and Model 2 (0.786) was not found, the NRI (8.312% [p < 0.001]) and IDI (0.700% [p = 0.012]) demonstrated that the performance of Model 2 improved compared with Model 1. In conclusion, results suggested that long-term SBPV slightly improved predictive utility for T2DM when added to a conventional prediction model. The study was registered at University Hospital Medical Information Network Clinical Trial registry (UMIN000052544, https://www.umin.ac.jp/).

Background: Long-term care facilities (LTCFs) remain highly vulnerable to COVID-19. Despite reduced virulence, Omicron’s high transmissibility poses ongoing risks. The effect of infection under strict control measures and early antiviral treatment remains unclear. Methods: We conducted a retrospective cohort study in a 450-bed LTCF, which implemented rigorous infection control and early antiviral use, evaluating survival outcomes during repeated Omicron outbreaks from January 2022 to December 2023 using Cox regression with time-dependent covariates, adjusted for age, sex, comorbidities, and vaccination status. Mortality trends were also compared across three periods: pre-COVID-19 (2018–2019), COVID-19 present in Japan but absent in our facility (2020–2021), and the Omicron outbreak period (2022–2023). Results: Among 623 residents, 253 were infected. Mortality was lower in the infected group than in the uninfected group (16% vs. 26%), and infection was not significantly associated with increased mortality (HR = 1.36; 95% CI: 0.91–2.04; p = 0.14). Although stratified analysis showed higher mortality among infected females, overall mortality during the outbreak period was unexpectedly lower than in prior periods. Conclusions: In LTCFs with rigorous infection control and early antiviral use, Omicron infection did not raise mortality. Enhanced protocols may have improved survival, even among uninfected residents.

BACKGROUND: Estimating the prevalence of schizophrenia in the general population remains a challenge worldwide, as well as in Japan. Few studies have estimated schizophrenia prevalence in the Japanese population and have often relied on reports from hospitals and self-reported physician diagnoses or typical schizophrenia symptoms. These approaches are likely to underestimate the true prevalence owing to stigma, poor insight, or lack of access to health care among respondents. To address these issues, we previously developed an artificial neural network (ANN)-based schizophrenia classification model (SZ classifier) using data from a large-scale Japanese web-based survey to enhance the comprehensiveness of schizophrenia case identification in the general population. In addition, we also plan to introduce a population-based survey to collect general information and sample participants matching the population's demographic structure, thereby achieving a precise estimate of the prevalence of schizophrenia in Japan. OBJECTIVE: This study aimed to estimate the prevalence of schizophrenia by applying the SZ classifier to random samples from the Japanese population. METHODS: We randomly selected a sample of 750 participants where the age, sex, and regional distributions were similar to Japan's demographic structure from a large-scale Japanese web-based survey. Demographic data, health-related backgrounds, physical comorbidities, psychiatric comorbidities, and social comorbidities were collected and applied to the SZ classifier, as this information was also used for developing the SZ classifier. The crude prevalence of schizophrenia was calculated through the proportion of positive cases detected by the SZ classifier. The crude estimate was further refined by excluding false-positive cases and including false-negative cases to determine the actual prevalence of schizophrenia. RESULTS: Out of 750 participants, 62 were classified as schizophrenia cases by the SZ classifier, resulting in a crude prevalence of schizophrenia in the general population of Japan of 8.3% (95% CI 6.6%-10.1%). Among these 62 cases, 53 were presumed to be false positives, and 3 were presumed to be false negatives. After adjustment, the actual prevalence of schizophrenia in the general population was estimated to be 1.6% (95% CI 0.7%-2.5%). CONCLUSIONS: This estimated prevalence was slightly higher than that reported in previous studies, possibly due to a more comprehensive disease classification methodology or, conversely, model limitations. This study demonstrates the capability of an ANN-based model to improve the estimation of schizophrenia prevalence in the general population, offering a novel approach to public health analysis.

Background Research on the influence of heart failure on mortality after Alzheimer's disease diagnosis is limited. Objective To evaluate the association between comorbid heart failure and mortality following Alzheimer's disease diagnosis, particularly considering sex differences. Methods We analyzed administrative claims data from Japan, involving 32,363 individuals (11,064 men and 21,299 women) aged 75 or older newly diagnosed with Alzheimer's disease, with 7% having comorbid heart failure. Cox proportional hazard models and population attributable fractions (PAFs) were used to evaluate the association between comorbid heart failure and mortality within one year following Alzheimer's disease diagnosis. Results Individuals with Alzheimer's disease and heart failure had a multivariate-adjusted hazard ratio of 1.51 (95% confidence interval [CI], 1.32–1.73) for mortality during the one-year follow-up period compared to those with Alzheimer's disease and without heart failure. Subgroup analysis by sex revealed a higher mortality hazard ratio in women of 1.63 (95% CI, 1.36–1.95) than that in men of 1.39 (95% CI, 1.13–1.71). Further age and sex subgroup analysis indicated that women across all age brackets—75–79, 80–84, and ≥ 85 years—had higher mortality hazard ratios. The PAF for heart failure increased with age in both sexes, with women having higher PAFs than men, and the sex difference in PAF being most pronounced in the 75–79 age category (men: 1.4%, women: 4.0%). Conclusions Hazard ratios and PAFs for mortality associated with comorbid heart failure in newly diagnosed Alzheimer's disease are higher in women than in men, which persists across all age subgroups.

PURPOSE: Tecnis Eyhance (DIB00V) is a type of monofocal intraocular lens (IOL) categorized as "IOL-plus", a new concept developed to improve not only distance but also intermediate vision. However, its negative effect, eg difficulty in macular surgery that is occasionally seen with the multifocal IOL, has not been ruled out in combined surgery for epiretinal membrane (ERM) and cataracts. This study aimed to compare DIB00V with a conventional monofocal IOL (DCB00V) in terms of visual acuity and patient-reported outcomes of combined surgery for epiretinal membrane (ERM) and cataracts. METHODS: This was a multicenter, prospective, nonrandomized, observational study conducted in Japan. Patients scheduled for combined cataract and pars plana vitrectomy (PPV) for cataract and ERM were enrolled. IOL was selected according to the rules originally applied in each facility. Best-corrected distance visual acuity (BCDVA) and distance-corrected intermediate visual acuity (DCIVA) at 3-month visits postoperatively, surgical parameters, and Japanese-modified Catquest-9SF Questionnaire scores were compared between the two IOL groups. RESULTS: Sixty-two eyes implanted with DCB00V (Tecnis-1) and 79 eyes implanted with DIB00V (Eyhance) were analyzed. There was no significant difference in BCDVA with Eyhance (0.09 in logMAR) and Tecnis-1 (0.05 in logMAR, p = 0.174), and DCIVA with Eyhance (0.35 in logMAR) and Tecnis-1 (0.39 in logMAR, p = 0.200). Rasch analysis of the Japanese-modified Catquest-9SF Questionnaire revealed that Eyhance scored higher in patients' general satisfaction (p = 0.0269). Subgroup analysis revealed a better postoperative distance-corrected intermediate visual acuity in patients with a certain degree of preoperative myopia (spherical error < -1.5 diopter). CONCLUSION: Eyhance provided comparable postoperative visual acuity to the conventional monofocal IOL in combined surgery for cataract and ERM, and surgical parameters are not different in the two types of IOL. Furthermore, Eyhance improved postoperative satisfaction in the overall population and significantly improved intermediate visual acuity in the preoperatively myopic population.

BACKGROUND: Difficulty in chewing has been shown to be associated with increased mortality, geriatric syndromes, and poor activities of daily living, indicating the need for intervention. Chewing difficulties are related to tooth loss, periodontitis, dry mouth, and a number of oral health conditions. Diabetes mellitus (DM) is one of the major causes of global burden of diseases, and has been associated with poor oral health. Prospective association between oral health status and the development of diabetes has also been reported. However, relationship between glycemic control and self-reported chewing difficulty remains less explored in working-age populations. The objective of this study is to cross-sectionally explore the association between fasting blood glucose (FBG) and self-reported chewing difficulty in adults working in a Japanese worksite. METHODS: Participants from the Aichi Workers' Cohort Study who responded to the 2018 survey were included. Participants were categorized into five FBG groups (<100, 100-109, 110-125, 126-159, and ≥160 mg/dl). Multivariable odds ratios (ORs) and 95% confidence intervals (CIs) for chewing difficulty were estimated using logistic regression adjusted for age, sex, body mass index, smoking and alcohol consumption status, number of teeth, presence of periodontal disease and the number of anti-diabetic medication classes. RESULTS: A total of 164 participants (4.2%) reported difficulty with chewing, the prevalence of which tended to increase with increasing FBG level. FBG ≥160 mg/dl was significantly and strongly associated with difficulty with chewing in the final multivariable model (multivariable OR 3.84 [95% CI 1.13-13.0]). CONCLUSIONS: A relationship between higher FBG levels and difficulty with chewing was observed, independent of potential confounding factors. However, prospective or interventional studies are needed to determine causality.

Objectives We evaluated the number of hospitalizations among public assistance recipients for each major classification according to the International Classification of Diseases 10th Revision (ICD-10), adjusting for sex and age differences in the general Japanese population. This study aimed to provide a comprehensive assessment of hospitalization patterns among public assistance recipients by disease category.Methods We used indirect methods to adjust for sex and age, with public assistance recipients and the entire Japanese population as the observation and reference groups, respectively. We calculated the standardized hospitalization ratios (SHRs) for each major classification based on the ICD-10. We only used publicly available government statistics, including data from the 2020 Patient Survey, for hospitalization rates according to sex, age, and major classification. Additionally, we used data from the 2020 National Survey on Public Assistance Recipients conducted for the number of public assistance recipients by sex and age groups and data from the 2020 Survey on the Actual Status of Medical Assistance conducted for the number of hospitalizations by major classification.Results After adjusting for age, the overall SHR was 1.49. The major classifications with the high SHRs for men and women were "V. Mental and behavioural disorders" (SHR for men; 4.06, women; 3.45) and "IV. Endocrine, nutritional, and metabolic diseases" (SHR for men; 2.40, women; 1.47). Conversely, the major classifications with low SHRs were "XVI. Certain conditions originating in the perinatal period" (SHR; 0.43) and "VII. Diseases of the eye and adnexa" (SHR; 0.44) for men. For women, these were "XV. Pregnancy, childbirth, and the puerperium" (SHR; 0.17) and "VII. Diseases of the eye and adnexa" (SHR; 0.27).Conclusion After adjusting for age, hospitalization status among public assistance recipients was higher overall than in the general Japanese population. However, if divided based on major classifications, higher and lower rates were observed compared with the general population. In assessing the status of medical assistance for public assistance recipients, research should be conducted by disease classification, considering the significant differences in age composition between public assistance recipients and the general Japanese population.

Aim Japan faces a public health challenge of dementia, further complicated by the increasing complications from diabetes within its rapidly aging population. This study assesses the impact of diabetes on mortality and hospitalization among individuals aged ≥75 years with new dementia diagnoses. Methods We analyzed administrative claims data in Japan from 73 324 individuals aged ≥75 years with dementia, of whom 17% had comorbid diabetes. Dementia and diabetes were identified from the International Classification of Diseases, Tenth Revision codes. We used Kaplan–Meier survival analysis, Cox proportional hazards analysis, and population attributable fractions (PAFs) to evaluate the impact on mortality and hospitalization after dementia diagnosis. Results One‐year mortality and 1‐year hospitalization probabilities in individuals with dementia and diabetes (10.3% and 31.7%, respectively) were higher than those without diabetes (8.3% and 25.4%, respectively). The adjusted hazard ratios for individuals with diabetes, as compared to those without, were 1.126 (95% confidence interval [CI], 1.040–1.220) for mortality and 1.191 (95% CI, 1.140–1.245) for hospitalization. The PAFs from the comorbidity of dementia and diabetes were 2.2% for mortality and 3.1% for hospitalization. Subgroup analysis showed that the PAFs were highest in men aged 75–79 years and women aged 80–84 years for mortality and in individuals aged 75–79 for hospitalization. Conclusion During the early postdiagnosis period, comorbid diabetes increases mortality and hospitalization risks in older adults with dementia. The variation in disease burden across age groups underscores the need for age‐specific health care strategies to manage comorbid diabetes in individuals with dementia. Geriatr Gerontol Int 2024; 24: 773–781.

Aim Several studies have shown that dairy consumption in old age is effective in preventing frailty. However, there is a lack of evidence regarding the association between milk consumption during middle age and the development of frailty in old age. Therefore, we carried out an investigation to explore the association between milk consumption during middle age and development of frailty examined after over 15 years of follow up in a long‐term cohort study in Japan. Methods We studied 265 participants aged 60–79 years (212 men and 53 women) in 2018, who participated in both the baseline survey in 2002 and the frailty assessment in 2018. The amount of milk consumption (g/day) at baseline was age‐ and energy‐adjusted, and classified into three categories (no, low and high consumption: 0 g/day, ≤135.86 g/day, &gt;135.86 g/day in men and 0 g/day, ≤126.44 g/day, &gt;126.44 g/day in women). Odds ratios (OR) and 95% confidence intervals (CI) for prefrailty/frailty after adjusting for lifestyles at baseline, stratified by sex, were estimated using logistic regression analysis. Results The prevalence of prefrailty/frailty in 2018 was 37.7% and 28.3% in men and women, respectively. Milk consumption categories were inversely associated with the prevalence of prefrailty/frailty in men (OR 0.34, 95% CI 0.14–0.84 in low consumption; OR 0.31, 95% CI 0.10–0.95 in high consumption; P &lt; 0.05), but not in women (OR 0.53, 95% CI 0.11–2.65; P = 0.44). Conclusions In this study, milk intake in middle‐aged men was inversely associated with the prevalence of prefrailty/frailty later in life. Geriatr Gerontol Int 2024; 24: 700–705.

Background and Objective: Excellent generalizability is the precondition for the widespread practical implementation of machine learning models. In our previous study, we developed the schizophrenia classification model (SZ classifier) to identify potential schizophrenia patients in the Japanese population. The SZ classifier has exhibited impressive performance during internal validation. However, ensuring the robustness and generalizability of the SZ classifier requires external validation across independent sample sets. In this study, we aimed to present an external validation of the SZ classifier using outpatient data. Methods: The SZ classifier was trained by using online survey data, which incorporate demographic, health-related, and social comorbidity features. External validation was conducted using an outpatient sample set which is independent from the sample set during the model development phase. The model performance was assessed based on the sensitivity and misclassification rates for schizophrenia, bipolar disorder, and major depression patients. Results: The SZ classifier demonstrated a sensitivity of 0.75 when applied to schizophrenia patients. The misclassification rates were 59% and 55% for bipolar disorder and major depression patients, respectively. Conclusions: The SZ classifier currently encounters challenges in accurately determining the presence or absence of schizophrenia at the individual level. Prior to widespread practical implementation, enhancements are necessary to bolster the accuracy and diminish the misclassification rates. Despite the current limitations of the model, such as poor specificity for certain psychiatric disorders, there is potential for improvement if including multiple types of psychiatric disorders during model development.

Abstract Objectives This study aimed to develop an approach to enhance the model precision by artificial images. Materials and Methods Given an epidemiological study designed to predict 1 response using f features with M samples, each feature was converted into a pixel with certain value. Permutated these pixels into F orders, resulting in F distinct artificial image sample sets. Based on the experience of image recognition techniques, appropriate training images results in higher precision model. In the preliminary experiment, a binary response was predicted by 76 features, the sample set included 223 patients and 1776 healthy controls. Results We randomly selected 10 000 artificial sample sets to train the model. Models’ performance (area under the receiver operating characteristic curve values) depicted a bell-shaped distribution. Conclusion The model construction strategy developed in the research has potential to capture feature order related information and enhance model predictability.

Background In Japan, challenges were reported in accurately estimating the prevalence of schizophrenia among the general population. Retrieving previous studies, we investigated that patients with schizophrenia were more likely to experience poor subjective well-being and various physical, psychiatric, and social comorbidities. These factors might have great potential for precisely classifying schizophrenia cases in order to estimate the prevalence. Machine learning has shown a positive impact on many fields, including epidemiology, due to its high-precision modeling capability. It has been applied in research on mental disorders. However, few studies have applied machine learning technology to the precise classification of schizophrenia cases by variables of demographic and health-related backgrounds, especially using large-scale web-based surveys. Objective The aim of the study is to construct an artificial neural network (ANN) model that can accurately classify schizophrenia cases from large-scale Japanese web-based survey data and to verify the generalizability of the model. Methods Data were obtained from a large Japanese internet research pooled panel (Rakuten Insight, Inc) in 2021. A total of 223 individuals, aged 20-75 years, having schizophrenia, and 1776 healthy controls were included. Answers to the questions in a web-based survey were formatted as 1 response variable (self-report diagnosed with schizophrenia) and multiple feature variables (demographic, health-related backgrounds, physical comorbidities, psychiatric comorbidities, and social comorbidities). An ANN was applied to construct a model for classifying schizophrenia cases. Logistic regression (LR) was used as a reference. The performances of the models and algorithms were then compared. Results The model trained by the ANN performed better than LR in terms of area under the receiver operating characteristic curve (0.86 vs 0.78), accuracy (0.93 vs 0.91), and specificity (0.96 vs 0.94), while the model trained by LR showed better sensitivity (0.63 vs 0.56). Comparing the performances of the ANN and LR, the ANN was better in terms of area under the receiver operating characteristic curve (bootstrapping: 0.847 vs 0.773 and cross-validation: 0.81 vs 0.72), while LR performed better in terms of accuracy (0.894 vs 0.856). Sleep medication use, age, household income, and employment type were the top 4 variables in terms of importance. Conclusions This study constructed an ANN model to classify schizophrenia cases using web-based survey data. Our model showed a high internal validity. The findings are expected to provide evidence for estimating the prevalence of schizophrenia in the Japanese population and informing future epidemiological studies.

Abstract Nonpharmaceutical interventions (NPIs) to control COVID‐19 have decreased the incidence of many pediatric infectious diseases. The epidemiology of β‐ and γ‐herpesvirus infections might have been affected by NPIs. The aim of this study was to elucidate changes in trends in β‐ and γ‐herpesvirus infections and complex febrile seizures (cFS) of viral etiology before and during the COVID‐19 pandemic. Between April 2017 and March 2021, febrile children aged ≤5 years were enrolled. Detection of EBV, CMV, HHV‐6B, and HHV‐7 DNA in serum was performed using real‐time PCR. The epidemiology of viral infections and cFS were compared between the prepandemic and pandemic periods. During the observation period, 1432 serum samples were collected. The mean number of febrile children decreased during the pandemic period, but the number of patients with HHV‐6B infection increased from 35 (9.3% of all febrile children) per year before the pandemic to 43 (15.5%) during the pandemic. The change in the proportion of patients with primary HHV‐6B infection was 6.50% (95% confidence interval [CI], 2.05%–11.3%; p = 0.0047). The mean number of patients with cFS decreased during the pandemic period, but the number of patients with HHV‐6B–associated cFS was stable throughout the observation period. Therefore, the change in proportion of patients with cFS caused by primary HHV‐6B infection was 49.5% (95% CI, 12.2%–60.5%; p = 0.0048). The disease burden of primary HHV‐6B infection among patients in the emergency room remained unchanged, with a significant increase in the relative proportion after the COVID‐19 pandemic began.

BACKGROUND: Lung cancer frequently occurs in lungs with background idiopathic interstitial pneumonias (IIPs). Limited resection is often selected to treat lung cancer in patients with IIPs in whom respiratory function is already compromised. However, accurate surgical margins are essential for curative resection; underestimating these margins is a risk for residual lung cancer after surgery. We aimed to investigate the findings of lung fields adjacent to cancer segments affect the estimation of tumor size on computed tomography compared with the pathological specimen. METHODS: This analytical observational study retrospectively investigated 896 patients with lung cancer operated on at Fujita Health University from January 2015 to June 2020. The definition of underestimation was a ≥10 mm difference between the radiological and pathological maximum sizes of the tumor. RESULTS: The lung tumors were in 15 honeycomb, 30 reticulated, 207 emphysematous, and 628 normal lungs. The ratio of underestimation in honeycomb lungs was 33.3% compared to 7.4% without honeycombing (P=0.004). Multivariate analysis showed that honeycombing was a significant risk factor for tumor size underestimation. A Bland-Altman plot represented wide 95% limits of agreement, -40.8 to 70.2 mm, between the pathological and radiological maximum tumor sizes in honeycomb lungs.

The physical, psychiatric, and social comorbidities interfere with the everyday activities of community-dwelling individuals with schizophrenia and increase the risk of their readmission. However, these comorbidities have not been investigated comprehensively in Japan. We conducted a self-reported internet survey in February 2022 to identify individuals aged 20–75 years with and without schizophrenia using a prevalence case-control study. The survey compared physical comorbidities such as being overweight, hypertension, and diabetes; psychiatric comorbidities such as depressive symptoms and sleep disturbances; social comorbidities such as employment status, household income, and social support between participants with and without schizophrenia. A total of 223 participants with schizophrenia and 1776 participants without schizophrenia were identified. Participants with schizophrenia were more likely to be overweight and had a higher prevalence of hypertension, diabetes, and dyslipidemia than participants without schizophrenia. Additionally, depressive symptoms, unemployment, and non-regular employment were more prevalent in participants with schizophrenia than those without schizophrenia. These results highlight the necessity of comprehensive support and interventions addressing physical, psychiatric, and social comorbidities in individuals with schizophrenia in the community. In conclusion, effective interventions for managing comorbidities in individuals with schizophrenia are necessary to enable them to continue to live in the community.

The aim of the present study was to derive dietary patterns to explain variation in a set of nutrient intakes or in the measurements of waist circumference (WC) and fasting blood glucose (FBG) using reduced rank regression (RRR) and to prospectively investigate these patterns in relation to the risk of developing metabolic syndrome (MetS) and its components during the follow-up. The study participants were comprised of 2944 government employees aged 30–59 years without MetS. RRR was applied with 38 food groups as predictors and with two sets of response variables. The first set included intake of putatively beneficial nutrients, and the first factor retained was named the Healthy Dietary Pattern (HDP). The second one included baseline WC and FBG, and the first factor was named the Unhealthy Dietary Pattern (UHDP). Multivariable Cox proportional hazard model was used to estimate hazard ratio and 95% confidence intervals with adjustments for age, sex, total energy consumption and other potential confounders. During the 5-year median follow-up, we ascertained 374 cases of MetS. The HDP score was inversely associated with the incidence of MetS (p-trend = 0.009) and hypertension (p-trend = 0.002) and marginally significantly associated with elevated triglyceride and decreased high-density lipoprotein cholesterol (p-trend = 0.08). The UHDP score was linearly positively associated with the incidence of MetS and all its components (all p-trend &lt; 0.05). Both the HDP and UHDP predicted the development of MetS and its components.

AIMS: The associations between low-density lipoprotein cholesterol (LDL-C) and the risk of cardiovascular disease (CVD) subtypes are not well established among the Japanese population. This study used longitudinal data from the Aichi Workers' Cohort Study to explore the association between LDL-C levels and the risk of coronary heart disease (CHD) and stroke subtypes. METHODS: Pooled data of 8966 adults (7093men and 1903 women) who were recruited between (2002) and (2008) were used for the current analysis. Propensity scores for the LDL-C categories were generated using multinomial logistic regression. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated from the inverse probability weighted Cox proportional hazards model for LDL-C category associations with risks of CHD, stroke subtypes, and CVD. RESULTS: During a median follow-up of 12 years, 122 strokes (57 ischemic strokes, 25 intracerebral hemorrhage, and 40 unknown subtypes) and 82 cases of CHD were observed. LDL-C 160- mg/dL compared to LDL-C 100-119 mg/dL was positively and significantly associated with the risk of CHD (HR: 4.56; 95% CI: 1.91-10.9) but not with ischemic stroke (HR: 0.99; 95% CI: 0.44-2.22). LDL-C was inversely associated with the risk of intracerebral hemorrhage (P for trend=0.009). CONCLUSION: In middle-aged Japanese workers, LDL-C was significantly and positively associated with CHD, but not with ischemic stroke. LDL-C was inversely significantly associated with intracerebral hemorrhage.

AIM: We aimed to examine the association of obesity-related cancer and cardiovascular disease (CVD) with body mass index (BMI) and the estimated population attributable fraction in lean Asians. METHODS: We studied 102,535 participants aged 40-79 years without histories of cancer or CVD at baseline between 1988 and 2009. The cause-specific hazard ratios (csHRs) of BMI categories (＜18.5, 18.5-20.9, 21.0-22.9 [reference], 23.0-24.9, 25.0-27.4, and ≥ 27.5 kg/m2) were estimated for each endpoint. The events considered were mortalities from obesity-related cancer (esophageal, colorectal, liver, pancreatic, kidney, female breast, and endometrial cancer) and those from CVD (coronary heart disease and stroke). Population attributable fractions (PAFs) were calculated for these endpoints. RESULTS: During a 19.2-year median follow-up, 2906 died from obesity-related cancer and 4532 died from CVD. The multivariable-adjusted csHRs (95% confidence interval) of higher BMI categories (25-27.4 and ≥ 27.5 kg/m2) for obesity-related cancer mortality were 0.93 (0.78, 1.10) and 1.18 (0.92, 1.50) in men and 1.25 (1.04, 1.50) and 1.48 (1.19, 1.84) in women, respectively. The corresponding csHRs for CVD mortality were 1.27 (1.10, 1.46) and 1.59 (1.30, 1.95) in men and 1.10 (0.95, 1.28) and 1.44 (1.21, 1.72) in women, respectively. The PAF of a BMI ≥ 25 kg/m2 for obesity-related cancer was -0.2% in men and 6.7% in women and that for CVD was 5.0% in men and 4.5% in women. CONCLUSION: A BMI ≥ 25 kg/m2 is associated with an increased risk of obesity-related cancer in women and CVD in both sexes.

PURPOSE: To investigate whether previously reported seasonal variation and winter-dominant prevalence of acute massive submacular hemorrhages (SMHs) caused by age-related macular degeneration (AMD) disappeared, and those caused by retinal microaneurysms (RMAs) emerged. METHOD: The medical charts of 95 patients (95 eyes) with SMH caused by AMD and 76 patients (76 eyes) with SMH caused by RMAs in 2012-2019 were retrospectively reviewed. For each subject, the month of onset, the mean ambient temperature of that month were recorded. RESULTS: The monthly numbers of cases of SMHs caused by AMD from January to December were 6, 8, 4, 9, 7, 10, 9, 11, 7, 11, 3, and 10. No significant seasonal variation in the monthly incidence was identified (Roger's R = 1.89, p = 0.39). The monthly numbers of SMHs caused by RMAs from January to December were 3, 11, 11, 8, 7, 8, 5, 5, 2, 4, 7, and 5. There was significant seasonal variation in the monthly incidence (Roger's R = 7.67, p = 0.02). There was no significant correlation between the monthly incidence of SMHs caused by RMAs and mean ambient temperature. CONCLUSION: Our previous study conducted for cases obtained in 1998-2005 showed seasonal cyclic trend in the number of SMHs caused by AMD, with the peak in winter. However, that significant seasonal variation disappeared in 2012-2019 in the present study. Common usage of OCT devices and anti-VEGF drugs might be the reason for the lack of seasonal variation in the cases of SMH caused by AMD.

BACKGROUND: Diabetes is a major risk factor for cardiovascular diseases (CVD). This systematic review aims to explore the work-related factors among people with diabetes in developing CVD. METHODS: Four electronic databases were searched on 1 February 2021 using a comprehensive search strategy without any time restriction. Two independent researchers screened the articles and extracted data. The risk of bias was assessed independently using the risk of bias assessment tool for non-randomized studies (RoBANS). A narrative synthesis was conducted considering the heterogeneity of the included articles. RESULTS: A total of five articles incorporating 4 409 810 participants from three geographic regions were included that highlights the research gap. As per the included studies, Occupational drivers with diabetes were at a higher risk of CVD in comparison to the nondrivers, workers with diabetes having a long working hour were at a higher risk of CVD mortality, workers with a lower occupational status were at a higher risk of 10-years stroke risk, and occupational physical activity and occupational commuting lowered the risk of CVD deaths. CONCLUSIONS: This systematic review summarized the available evidence on work-related factors influencing the risk of CVD in people with diabetes. The findings should be interpreted cautiously pondering the limited evidence and imprecision. We identified only five articles related to the topic, and there were no studies from Japan. The scarcity of studies on work-related factors on the prognosis of diabetic patients implies the need for more research in this field. We recommend further exploration of the topic designing primary studies.

BACKGROUND: The aim of this study was to determine the effectiveness of the Smart Life Stay (SLS) program, which is an experience-oriented stayover program, in combination with health tourism and mandatory health guidance on glucose metabolism after 2 years. METHODS: The participants of the SLS program (n = 792) were recruited from a database of 23 medical insurers. They underwent a mandatory health examination termed Specific Health Checkups in 2014. The participants were included if they had diabetes or were at a high risk of diabetes and if they satisfied the following inclusion criteria: (1) body mass index (BMI; kg/m2) > 25, or (2) waist circumference (WC; cm) > 85 for men and > 90 for women, or (3) hemoglobin A1c (HbA1c; %) > 5.6, or (4) fasting plasma glucose (FPG; mg/dl) > 100. Individuals who corresponded to one or more items were included as study participants. The control subjects (n = 3645) were nonparticipants of the program who were selected from the database and met the inclusion criteria. The lifestyle changes and changes in mean BMI, WC, FPG, and HbA1c in both groups from baseline to 2-year follow-up were compared by inverse probability weighting of a propensity score. RESULTS: The percentage of people who exercised regularly increased significantly in the SLS group compared with the control group. In the SLS group, BW, BMI, and WC significantly decreased by 1.75 kg, 0.60 kg/m2, and 1.45 cm, respectively, whereas in the control group, WC, FPG, and HbA1c increased significantly by 0.38 cm, 3.37 mg/dl, and 0.12%, respectively. The comparison between groups revealed that the BW, BMI, WC, FPG, and HbA1c improved significantly in the SLS group. CONCLUSIONS: The SLS program is suggested to help improve glucose metabolism. This program could be a feasible option as a lifestyle intervention program for diabetes.

BACKGROUND: Relatively little evidence exists for type 2 diabetes mellitus (T2DM) prediction models from long-term follow-up studies in East Asians. This study aims to develop a point-based prediction model for 10-year risk of developing T2DM in middle-aged Japanese men. METHODS: We followed 3,540 male participants of Aichi Workers' Cohort Study, who were aged 35-64 years and were free of diabetes in 2002, until March 31, 2015. Baseline age, body mass index (BMI), smoking status, alcohol consumption, regular exercise, medication for dyslipidemia, diabetes family history, and blood levels of triglycerides (TG), high density lipoprotein cholesterol (HDLC) and fasting blood glucose (FBG) were examined using Cox proportional hazard model. Variables significantly associated with T2DM in univariable models were simultaneously entered in a multivariable model for determination of the final model using backward variable selection. Performance of an existing T2DM model when applied to the current dataset was compared to that obtained in the present study's model. RESULTS: During the median follow-up of 12.2 years, 342 incident T2DM cases were documented. The prediction system using points assigned to age, BMI, smoking status, diabetes family history, and TG and FBG showed reasonable discrimination (c-index: 0.77) and goodness-of-fit (Hosmer-Lemeshow test, P = 0.22). The present model outperformed the previous one in the present subjects. CONCLUSION: The point system, once validated in the other populations, could be applied to middle-aged Japanese male workers to identify those at high risk of developing T2DM. In addition, further investigation is also required to examine whether the use of this system will reduce incidence.

OBJECTIVE: To examine whether laughter yoga (LY), i.e., simulated laughter, alters cortisol and dehydroepiandrosterone (DHEA) levels and cortisol/DHEA (C/D) ratios. METHODS: In a randomized controlled trial, 120 healthy university students were allocated to experiencing LY, watching a comedy movie (spontaneous laughter), or reading a book. Salivary cortisol and DHEA levels were measured immediately before, immediately after, and 30 min after the intervention. RESULTS: Cortisol levels and C/D ratios significantly decreased by time in the LY and comedy movie groups. Significant group*time interactions were found between these two groups for cortisol levels and C/D ratios. DHEA levels did not change by time in the LY group. CONCLUSIONS: LY decreased cortisol levels and C/D ratios but did not affect DHEA levels. Simulated and spontaneous laughter differently affected the dynamics of cortisol levels and C/D ratios. Effect of spontaneous laughter on the cortisol dynamics lasted longer than that of simulated laughter. (UMIN000019409).

国際的には低い冠動脈疾患発症率を誇るわが国ではあるが、肥満や不活発な生活習慣の蔓延による耐機能異常、脂質異常の割合の増加により、男性、特に都市部男性における発症率の増加が示唆されている。わが国における冠動脈疾患の危険因子(高血圧、脂質異常症、糖尿病、喫煙、肥満、メタボリックシンドローム、慢性腎臓病、飲酒)について、定義、冠動脈疾患発症、死亡との関連の特徴などについて個々に概説した。

癌サバイバーである日本人労働者の機能的能力(FC)、自己評価健康状態(SRHS)および心理社会的特性(PSC)を評価し、これらの特性を癌サバイバー労働者(癌既往群)と癌無病歴労働者(癌非既往群)との間で比較した。対象は2113年の地方自治体職員5474名(癌既往群112名)で、自己記入質問票を用いてFC、SRHSおよびPSC(社会的支援、自覚ストレス、社会資本、生き甲斐、幸福)における制限を評価し、癌病歴がこれらの制限に関連するか否か検討した。その結果、癌既往群では全年齢の男性と比較的若い女性がいずれも対応する癌非既往群よりFCの制限が多く(全年齢の男性14.5%対2.9%:50歳未満の女性15.2%対1.1%)、全年齢の男性が非既往群に比べてSRHSが悪かった(8.1%対1.5%)。一方、PSCは両群間で有意な差が見られなかった。以上より、男性と比較的若い女性の癌サバイバーである労働者はFCの制限が多く、男性ではSRHSも悪いと考えられた。

BACKGROUND AND AIMS: Coronary heart disease (CHD) and stroke have common risk factors, but some of these differ in the magnitude or direction of associations between CHD and stroke. We assessed whether the impact of each risk factor differed between CHD and stroke mortality in Asians. METHODS: In total, 104 910 subjects aged 40-79 years without histories of cancer, CHD and stroke at baseline were followed between 1988 and 2009. Competing-risks analysis was used to test for differences in the associations of each risk factor with two endpoints (CHD and stroke). Population attributable fractions (PAFs) were also calculated for these endpoints to estimate the population impact of each risk factor. RESULTS: During a median 19.1-year follow-up, 1554 died from CHD and 3163 from stroke. The association of hypertension with CHD was similar to that with stroke in terms of the magnitude and direction (multivariable-adjusted hazard ratio for CHD: 1.63 vs. stroke: 1.73 in men and 1.70 vs. 1.66 in women). Conversely, the magnitude of these associations differed for smoking (CHD: 1.95 vs. stroke: 1.23 in men and 2.45 vs. 1.35 in women) and diabetes (1.49 vs. 1.09 in men and 2.08 vs. 1.39 in women). The highest PAF for CHD was caused by smoking in men and by hypertension in women; that for stroke was caused by hypertension in both sexes. CONCLUSIONS: Hypertension associations and PAFs were consistent between CHD and stroke, but not for other risk factors. These findings may be useful to optimize public health intervention strategies.